Jet pump with rotatable venturi cartridge

Abstract

A jet pump having a rotatable venturi cartridge to permit any of several different sized venturi tubes to be aligned with a nozzle in the pump casing. A knob is provided on the pump casing to permit convenient rotation of the venturi cartridge. Printed indicia on the knob align with an indicator arrow to visually indicate the setting of the knob.

Having thus described the invention, I claim: 
     
       1. In a jet pump having a casing presenting a pump inlet and a pump outlet and a driven impeller rotatable about a first axis for effecting a pressure differential between the pump inlet and outlet to pump liquid therebetween, the improvement comprising: a converging nozzle disposed to pass liquid therethrough, said nozzle tapering from an inlet thereof to a restricted outlet thereof and having said outlet communicating with the pump inlet to effect a pressure reduction on the outlet side of the nozzle upon flow of liquid therethrough;   venturi means providing a flow path for liquid between the pump inlet and pump outlet substantially perpendicular to the first axis, said venturi means having a plurality of different venturi tubes each having a converging inlet, a restricted throat and a diverging outlet with the throats of the respective venturi tubes having different diameters;   means for mounting said venturi means in the casing in a manner permitting each venturi tube to be selectively aligned with said outlet of the nozzle in an operative position wherein the aligned tube provides said flow path; and   means accessible from the exterior of the pump for effecting selective alignment of each venturi tube with said nozzle.   
     
     
       2. The improvement of claim 1, wherein: said venturi means comprises a venturi cartridge carrying said venturi tubes thereon; and   said mounting means comprises means for mounting said cartridge for rotation in the casing along a rotary path carrying the venturi tubes into successive alignment with said nozzle.   
     
     
       3. The improvement of claim 2, wherein said means accessible from the exterior of the pump comprises a knob on the exterior of the casing coupled with said cartridge in a manner to effect rotation thereof when the knob is turned. 
     
     
       4. The improvement of claim 3, including means associated with said knob for visually indicating which venturi tube is aligned with said nozzle. 
     
     
       5. The improvement of claim 1, including means for visually indicating which venturi tube is aligned with said nozzle. 
     
     
       6. A jet pump comprising: a pump casing having a pump inlet for receiving incoming liquid and a pump outlet for discharging liquid;   an impeller in the pump casing and rotatable about a first axis;   drive means for driving said impeller about said axis to effect a pressure differential between the pump inlet and outlet to effect pumping of liquid therebetween along a main flow path;   a converging nozzle in the pump casing tapering from an inlet thereof to a restricted outlet thereof, said inlet being disposed to receive liquid at a relatively high pressure and said outlet communicating with the pump inlet to effect a pressure reduction when liquid passes through the nozzle;   a venturi cartridge having a plurality of venturi tubes each extending substantially perpendicular to said axis and having a converging inlet end, a restricted throat and a diverging outlet end, each venturi tube having a throat diameter different from the throat diameters of the other venturi tubes;   means for mounting said cartridge in the pump casing for movement along a presaribed path carrying said venturi tubes into successive alignment with the outlet of said nozzle with the aligned tube forming part of the flow path; and   means on the exterior of the pump casing for effecting selective movement of said cartridge along said prescribed path.   
     
     
       7. The jet pump of claim 6, wherein said mounting means comprises means for mounting said cartridge for rotation along said prescribed path about a rotational axis, each tube having a center displaced from said rotational axis the same distance as the other tubes. 
     
     
       8. The jet pump of claim 7, wherein said means on the exterior of the pump casing comprises a knob coupled with said cartridge in a manner to effect rotation thereof when the knob is turned. 
     
     
       9. The jet pump of claim 8, including means associated with said knob for visually indicating which venturi tube is aligned with said nozzle. 
     
     
       10. The jet pump of claim 6, including means for visually indicating which veturi tube is aligned with said nozzle. 
     
     
       11. The jet pump of claim 6, including detent means for releasably retaining said cartridge at a plurality of positions corresponding to positions of alignment between the venturi tubes and nozzle. 
     
     
       12. In a jet pump of the type having a pump casing presenting a pump inlet and a pump outlet and a driven impeller rotatable about a first axis for effecting a pressure differential between the pump inlet and pump outlet to pump liquid therebetween, the improvement comprising: a nozzle fixed in the pump casing and having an inlet disposed to receive liquid at a relatively high pressure, said nozzle tapering from said inlet thereof to an outlet thereof to effect a pressure reduction at said outlet of the nozzle at a location communicating with the pump inlet;   a venturi cartridge having a plurality of venturi tubes each extending substantially perpendicular to the axis and having a converging inlet end, a restricted throat and a diverging outlet end, said throats having different diameters and said cartridge being mounted in the pump casing for rotation along a path carrying said venturi tubes successively into alignment with the outlet of said nozzle to receive liquid for passage to the pump outlet; and   a knob on the exterior of the pump casing coupled with said cartridge in a manner to effect rotation of the cartridge when the knob is turned.   
     
     
       13. The improvement of claim 12, including releasable detent means for retaining said cartridge at positions wherein the venturi tubes are aligned with said nozzle. 
     
     
       14. The improvement of claim 12, including means for visually indicating which venturi tube is aligned with said nozzle.